OneImage

Aspect Ratio Guide

Understanding aspect ratios is essential for professional image work. This guide explains when and why to use each ratio.

Start Cropping

Common Aspect Ratios

1:1

1:1 Square

Perfect for social grids, profile images, and balanced compositions. The most versatile ratio.

Best For

  • Instagram posts
  • Profile pictures
  • Product thumbnails
1080×1080512×512256×256
4:5

4:5 Portrait

Maximizes vertical space in feeds while maintaining good balance. Instagram's preferred portrait ratio.

Best For

  • Instagram feed posts
  • Product shots
  • Portrait photography
1080×1350800×1000
16:9

16:9 Widescreen

The modern video standard. Used for YouTube, presentations, and HD displays.

Best For

  • YouTube thumbnails
  • Video content
  • Presentations
1920×10801280×7202560×1440
9:16

9:16 Vertical

The mobile-first format for stories, reels, and short-form video.

Best For

  • Instagram Stories
  • TikTok
  • Reels
1080×1920
3:2

3:2 Photography

Classic 35mm photography ratio. Natural for landscapes and prints.

Best For

  • Photography
  • 4×6 prints
  • Portfolio work
1800×12003000×2000
2:3

2:3 Portrait

Vertical counterpart of 3:2. Great for portraits and posters.

Best For

  • Portrait photography
  • Posters
  • Book covers
1200×18002000×3000
4:3

4:3 Standard

Classic display ratio. Good for presentations and tablets.

Best For

  • Presentations
  • iPad content
  • Documentation
1600×12001024×768
21:9

21:9 Ultrawide

Cinematic format for dramatic banners and immersive headers.

Best For

  • Website banners
  • Cinematic headers
  • Panoramic shots
2560×10803440×1440

Quick Reference

RatioNameBest ForCommon Sizes
1:11:1 SquareInstagram posts, Profile pictures1080×1080, 512×512, 256×256
4:54:5 PortraitInstagram feed posts, Product shots1080×1350, 800×1000
16:916:9 WidescreenYouTube thumbnails, Video content1920×1080, 1280×720, 2560×1440
9:169:16 VerticalInstagram Stories, TikTok1080×1920
3:23:2 PhotographyPhotography, 4×6 prints1800×1200, 3000×2000
2:32:3 PortraitPortrait photography, Posters1200×1800, 2000×3000
4:34:3 StandardPresentations, iPad content1600×1200, 1024×768
21:921:9 UltrawideWebsite banners, Cinematic headers2560×1080, 3440×1440

Try Different Ratios

Upload an image and experiment with different aspect ratios.

Export

Estimated size: -
40%90%100%
Export pixelsFollow crop & preset

Use the crop size from your preset; no extra resampling.

💡 ⌘/Ctrl+E 快速导出📐 Output size:

FAQ

Which aspect ratio should I use for social media?+
It depends on the platform. Use 1:1 for Instagram grid posts, 4:5 for maximum feed visibility, 9:16 for stories/reels, and 16:9 for YouTube thumbnails.
What's the difference between 16:9 and 9:16?+
16:9 is horizontal (widescreen), while 9:16 is vertical (mobile/stories). They're the same ratio rotated 90 degrees.

Ready to crop with the perfect ratio?

Select any aspect ratio and start cropping. Free, fast, and private.

Start Cropping
Aspect Ratio Guide – Choose the Right Crop for Any Use